U.S. patent # 8,739,720
- can set balanced sail with single spar
- sickle shape offers balanced rotation
- utilizes swept-back, efficient, aerodynamic cross sections
- can present self-rotating curvature along full length of mast in airflow
- not a conventional wing rig so does not misbehave at anchor (can be turned off quickly and completely!)
- stores well along gunwale of average boat
- looks cool to art majors and bird lovers
Muri-Maru, a 17' 5" birdwing Yangtze Pelican microcruiser
The following recently completed 3D renderings of a Yangtze Pelican birdwing ketch are from the desk of JF Bedard of Bedard Yacht Design. The boat design itself is the work of Captain William Short, a legendary tugboat captain of the San Francisco Bay area. The birdwing masts are my invention, U.S. patent # 8,739,720. The sail design is by Jeff Frank of Sailrite Interprises.
It has taken me a long time to get a good look at the true potential of birdwing masts. When they are rendered in carbon fiber it is likely that only then will they fulfill their greatest performance potential. It’s not a big trade secret that carbon fiber is wonderful stuff. That’s why it’s used in so many machines and vehicles these days. However, there’s something to be said for laminated spruce in a sailboat mast. It’s pretty for one thing. If you’re going to have to look at a stick holding up your sail all day long, might as well be a good looking mast. Spruce is also quite durable as well as strong – especially laminated. Spruce also machines well and shapes well so it has been good for my material of choice when making prototypes.
In the future birdwing masts might be made of a variety of materials depending on the type of sailing required. Applied to sail-assisted shipping birdwing masts could be pressure shaped aluminum. The birdwing shape is not an easy shape to manufacture unless a handcrafted one could be used to create a mold for multiple casting in carbon fiber and fiberglass. Or perhaps computer rendering of a birdwing mast could control a CNC milling machine that would in turn shape the perfectly aerodynamically efficient birdwing mast and that one could be duplicated. The reality is the birdwing mast is a shape. You only have to calculate how to achieve that shape once and then you can do it again. I’ve watched too many episodes of “How it’s made” to doubt that birdwing masts could be mass-produced.
In exploring the birdwing mast I’ve also taken a page from the Wright Brothers book, “How we invented the airplane,” by attaching the design to a bicycle.
Laugh if you want but it gave me a direct connection of how it was reacting to the wind that you do not necessarily get with a sailboat. It developed a good amount of power for bicycling under sail at the beach.
I’m currently working to complete the headsail for the birdwing bicycle.
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